This topic contains a solution. Click here to go to the answer
« previous next »

Author Question: Why do we believe galaxy clusters are rich in dark matter? What will be an ideal ... (Read 39 times)

jayhills49

  • Hero Member
  • *****
  • Posts: 559
on: Jul 27, 2018
Why do we believe galaxy clusters are rich in dark matter?
 
  What will be an ideal response?

Question 2

Why is Cygnus X-1 considered such a good black hole candidate?
 
  What will be an ideal response?


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

zhanghao

  • Sr. Member
  • ****
  • Posts: 316
Reply #1 on: Jul 27, 2018
Answer to Question 1

Studies of the gravitational interaction of clusters reveal they have 10-100 times more mass than is visible.

Answer to Question 2

The massive visible star is pulled around by an invisible massive companion in a 5.6 day orbit. If the visible star is a giant of 30 solar masses, then the companion must be close to 10 solar masses, well over the 3 solar mass limit for black holes. Also, the matter pulled off the visible star is seen to be flowing toward the dark companion, where it generates much X-rays in the accretion disk.


jayhills49

  • Member
  • Posts: 559
Reply 2 on: Jul 27, 2018
YES! Correct, THANKS for helping me on my review

irishcancer18

  • Member
  • Posts: 310
Reply 3 on: Yesterday
Great answer, keep it coming :)

« previous next »
 

Did you know?

A headache when you wake up in the morning is indicative of sinusitis. Other symptoms of sinusitis can include fever, weakness, tiredness, a cough that may be more severe at night, and a runny nose or nasal congestion.

Did you know?

Your skin wrinkles if you stay in the bathtub a long time because the outermost layer of skin (which consists of dead keratin) swells when it absorbs water. It is tightly attached to the skin below it, so it compensates for the increased area by wrinkling. This happens to the hands and feet because they have the thickest layer of dead keratin cells.

Did you know?

Cocaine was isolated in 1860 and first used as a local anesthetic in 1884. Its first clinical use was by Sigmund Freud to wean a patient from morphine addiction. The fictional character Sherlock Holmes was supposed to be addicted to cocaine by injection.

Did you know?

The calories found in one piece of cherry cheesecake could light a 60-watt light bulb for 1.5 hours.

Did you know?

Each year in the United States, there are approximately six million pregnancies. This means that at any one time, about 4% of women in the United States are pregnant.

Pigmented bands in nail of patient with dark skin Pigmented bands in nail of patient with dark skin
Clusters and Zones in the Olfactory Bulb Clusters and Zones in the Olfactory Bulb
Structural MRIs reveal cortical loss in adolescent patients with schizophrenia. Here dark blue ... Structural MRIs reveal cortical loss in adolescent patients with schizophrenia. Here dark blue ...
Cannons - Footsteps In The Dark (The Isley Brothers Cover) Cannons - Footsteps In The Dark (The Isley Brothers Cover)
The heart and its major blood vessels. Oxygen-rich blood is pumped from the lungs to the left The heart and its major blood vessels. Oxygen-rich blood is pumped from the lungs to the left
Venn diagram representation of 17,067 medium and large clusters of protein Venn diagram representation of 17,067 medium and large clusters of protein
Video: Major Elements in Biological Molecules: Carbohydrates

For a complete list of videos, visit our video library